1. Field of the Invention
The present invention relates to an apparatus and a method for providing additional information using an extension subtitles file, and more particularly, to an apparatus and a method for providing additional information using an extension subtitles file that can provide a user with additional information by adding additional information on images and subtitles to a synchronized subtitles file.
2. Description of the Related Art
The synchronized accessible media interchange technology (SAMI) of Microsoft Corporation and the real-text technology of RealNetworks, Inc. are conventional text-based captioning technologies. The conventional text-based captioning technologies have a structure of displaying captions based on synchronous time information of video stream data provided on a file in which the video stream data is recorded or via a network.
FIG. 1 shows a general caption file employing the SAMI format and parsed caption information. SAMI are advantageous as they are easy to produce and convenient to handle.
As illustrated, the method involves a SAMI file consisting of caption language in the extensible markup language (XML) format, and a parser to interpret the language. The caption language includes a time sync, caption content by language, and information on the size or color of a font, as necessary.
Operations to play text-based captions will be considered. Time sync (frame position) and text (speech) are extracted from a caption file by an internal XML parser read out by a caption processing unit and are stored in a memory. Caption text in a concerned frame position is checked, synchronized with image data, and then displayed when images are displayed on a frame basis.
For example, an XML parser extracts information about an English word “one” or a French word “un” located at time sync “1000”, and an English word “two” or a French word “deux” located at time sync “2000” from the caption file. Next, the XML parser synchronizes and displays the parsed data with the image data at the concerned time sync.
FIG. 2 shows a screen displaying image data and caption text synchronized by processing a conventional caption language.
Referring to FIG. 2, a device to play text-based captions displays caption data on a predetermined space of the screen for a predetermined time while playing videos after having read the video stream data and caption data.
However, it is difficult for the conventional caption language to represent information other than captions (for example, additional information on a caption) because it only includes an extremely small part of an HTML tag. Also, the conventional caption language is limited in the variety of additional information it can provide because only a script format is displayed providing information to a user.
Korean Unexamined Patent Publication No. 2004-033766 (Servicing Method of Summaries and Value Added Information on Videos Using Video Metadata on Internet) discloses a method comprising storing a variety of additional information on places, music, characters or goods included in a video in video metadata, together with a key frame (representative image) summarizing the content of the video, automatically synchronizing the variety of additional information stored in the video metadata with a video play time when the video is played, thereby displaying additional information corresponding to the video play time. However, this method is directed to playing a video and a variety of additional information contained in the video at the same time when the video on demand (VOD) service is provided over the Internet, and it does not disclose a technology for displaying predetermined additional information that is included in a general SAMI file.